fix(core): raw channel message type regression (#13268)

* Fix raw channel message type regression

* Re-word change file

* Rename formated_bytes to bytes_as_json_array

Author: Legend-Master

.changes/fix-channel-raw-message-type.md

@@ -0,0 +1,5 @@
+---
+tauri: patch:bug
+---
+
+Fix a regression that made the raw type messages received from `Channel.onmessage` became `number[]` instead of `ArrayBuffer` when that message is small

crates/tauri/src/ipc/channel.rs

@@ -154,9 +154,9 @@ impl JavaScriptChannelId {
             ))?;
           }
           InvokeResponseBody::Raw(bytes) if bytes.len() < MAX_RAW_DIRECT_EXECUTE_THRESHOLD => {
+            let bytes_as_json_array = serde_json::to_string(&bytes)?;
             webview.eval(format!(
-              "window['_{callback_id}']({{ message: {}, index: {current_index} }})",
-              serde_json::to_string(&bytes)?,
+              "window['_{callback_id}']({{ message: new Uint8Array({bytes_as_json_array}).buffer, index: {current_index} }})",
             ))?;
           }
           // use the fetch API to speed up larger response payloads
@@ -246,9 +246,9 @@ impl<TSend> Channel<TSend> {
             webview.eval(format!("window['_{callback_id}']({string})"))?;
           }
           InvokeResponseBody::Raw(bytes) if bytes.len() < MAX_RAW_DIRECT_EXECUTE_THRESHOLD => {
+            let bytes_as_json_array = serde_json::to_string(&bytes)?;
             webview.eval(format!(
-              "window['_{callback_id}']({})",
-              serde_json::to_string(&bytes)?,
+              "window['_{callback_id}'](new Uint8Array({bytes_as_json_array}).buffer)",
             ))?;
           }
           // use the fetch API to speed up larger response payloads